Electrostatic actuators and ultrasonic transducers may be used for various applications in a variety of media including liquids, solids and gas. For instance, ultrasonic transducers are commonly used in the medical field, such as for imaging, diagnostics, and therapy. Other uses may include biochemical imaging, non-destructive evaluation of materials, sonar, communications, proximity sensing, gas flow measurements, in-situ process monitoring, acoustic microscopy, underwater sensing and imaging, and numerous other practical applications.
An ultrasonic transducer having an electrostatic mechanism may be referred as a capacitive ultrasonic transducer. A capacitive ultrasonic transducer fabricated using micromachining techniques may be referred to as a capacitive micromachined ultrasonic transducer (CMUT). A typical CMUT may include at least two electrodes and a transducing space (e.g., a separation gap) between the two electrodes that allows one of the electrodes to be physically displaced toward and away from the other electrode during operation. For example, some CMUTs may include a flexible membrane that allows displacement of one or more of the electrodes. However, the displacement capability of such membranes may be limited due to various factors, such as the materials used, the physical configurations of the membranes and the CMUTs in which they are employed, and so forth.